<p>The present invention relates to digitally signing of electronic documents which are to be kept secure for a very long time, thereby taking into account future cryptographic developments which could render current cryptographic key-lengths insufficient. In accordance with the invention a double signature is issued for each document. A first digital signature (DTS) ensures the long time security, whilst a second digital signature (DUS) ensures the involvement of an individual user. Thereby, the second digital signature is less computationally intensive in its generation than the first digital signature.</p>
申请公布号
WO2004079986(A1)
申请公布日期
2004.09.16
申请号
WO2004IB00626
申请日期
2004.03.03
申请人
INTERNATIONAL BUSINESS MACHINES CORPORATION;BUHLER, PETER;OSBORNE, MICHAEL;MAEDER, ROMAN;KURSAWE, KLAUS
发明人
BUHLER, PETER;OSBORNE, MICHAEL;MAEDER, ROMAN;KURSAWE, KLAUS